This is the Allsky1 Camera System running at SCGO since 2006 December (now 8 years old!) It is an ST237A SBIG
camera with an integrated wide angle lens mounted inside a wooden housing with a 14″ dome. Heaters had to be installed inside the dome to keep condensation from forming when the air cooled down at night. We use wire wound resistors at about 18 watts from a 24vdc source. In addition a circulation fan (a small 12vdc fan from a computer power supply) had to be installed as well.
Over time we have had some issues:
The 12vdc fans fail quite frequently. Bugs get inside the dome and leave “presents” on the lens. 18 watts is a lot of heat and the wood has scarred a bit. Birds would often rest on top of it and leave presents. Water sometimes gets inside. So we decided to do a renovation in the next few days. The internal flat black mask that sits over the lens to block out local light pollution often moves around (especially in high winds when the entire post moves a bit)
The housing and 14″ dome will be tossed, the camera will be mounted directly to the post, a smaller resistor will be mounted on top of the camera but out of the line of sight of the lens, a variable power source 4-12vdc will be used to power it, giving it maybe 1-4 watts of heating ability, and a smaller 4″ dome will be attached on top of the camera assembly.
So, we have a smaller footprint for birds not to sit on, a smaller area at the top especially, a much smaller volume of air to heat, much less wattage going into heating, no fans needed, and a newer better optical quality dome (after 8 + years, the dome is a bit grungy). If need be the heating resistor can be placed to block local neighbours lights.